This invention relates in general to display systems and more specifically to binocular systems presenting different views from electronic image sources.
Head-mounted displays (HMDs) are useful for immersing a viewer in an artificial, or enhanced, visual world. Uses for HMDs include simulation systems, virtual reality applications, night vision, infravision, instrumentation displays and video games. In a binocular HMD separate views are presented to each of the user's left and right eyes. The use of separate views for each eye gives greater realism as the user is able to perceive stereo, or depth, effects.
It is common for the views to be generated by a computer using a digital imaging device such as a liquid crystal display. In such a system, each of the user's eyes is presented with a view from a separate image source. The presentation from the image source can be direct, reflected, partially reflected, or a combination of these. Often the views will partially overlap to provide a binocular view from the imager sources. This approach can be used, for example, to provide a stereo view. Another use for overlapping views is to have a high-resolution image source in one eye overlapping with a lower-resolution image source in the other eye. Typically, the high-resolution image is at the center of focus of the viewer--the point at which the viewer desires a high level of detail.
However, a problem exists with overlapping views from imager sources. This is because the boundary of overlap inevitably results in a visible line. In the case where a high-resolution image is overlapped within a low-resolution image, a visible line artifact around the high-resolution image conflicts with the desired view. The line is a result of the user's eye moving to reveal different areas within the viewfinder, sometimes disclosing portions of the edges of the physical image display device within the viewfinder such as the edges of a liquid crystal display panel used to produce the high-resolution image.
Thus, it is desirable to provide a system where line artifacts are minimized in imaging systems that overlay images presented to each eye.